Summary

More than 60 years ago, Hodgkin and Huxley showed that neurons maintain their negative resting membrane potential by leaking potassium ions (1). In most cells, the Na+- and K+-dependent adenosine triphosphatase (Na+, K+-ATPase) builds up high concentrations of extracellular sodium and intracellular potassium, and because the membrane is more permeable to potassium, there is a net flow of positive ions out of the cell. The channels responsible for the permeability were much later identified to be the twoépore domain potassium (K2P) channels (2). On pages 432 and 436 of this issue, Miller and Long (3) and Brohawn et al. (4) report the structures of the human K2P channels TWIK-1 and TRAAK.